SMPT errors in Firewall

[speedracercjr]

I've noticed that everyonce in a while i will get an error message in our firewall that says MAIL.DOMAIN.COM tried to send an EHLO message to XXX.DOMAIN.COM

What is this EHLO? Mail, as far as I can tell flows in and out with no problems. Just every once in a while this will show up in the firewall logs.

 

[brontosaurus]

same as HELO, with the addition of some server-specific info (like capabilities) that's returned from the host machine.

 

[speedracercjr]

So should I allow this to go throught the firewall? What's HELO? Is that that like a "handshake" for email servers?

 

[brontosaurus]

exactly, it's a greeting. most servers won't allow you to continue without being polite and introducing yourself .
It's OK to let it through, but if it's not causing you problems, don't worry.